1. Field of the Invention
This invention relates to a code regenerative system adapted to constitute a data communicating system mainly using a radio circuit and constructed to receive a binary code (a code representing "1" or "0") supplied in a series manner with respect to time from a transmission side and regenerate at a reception side a regenerative code synonymous with the code supplied from the transmission side according to a time base for the serializing of the code. More particularly, this invention relates to a code regenerative system which is capable of increasing a noise resistant property with respect to an electric noise in a radio circuit to improve the error rate of a code (hereinafter referred to as "bit error rate").
2. Description of the Prior Art
An improvement in bit error rate of a character or a sentence transmitted by means of a code has been conventionally carried out utilizing various steps including an error detection such as a parity check or the like, an error correction using a cyclic code, and the like.
Such a conventional step is adapted to introduce an unused lengthy code into a code system to increase a distance between a code representing a data to be transmitted and a code representing another data in proximity to the former data. Accordingly, when any error generates in a code, the code having the error constitutes a non-use lengthy code unless the amount of movement of the code due to the error is equal to the distance between the codes. Thus, the conventional steps require to discriminate the unused lengthy code every predetermined check interval or block to carry out an error check, followed by removing the block having an error code or converting the lengthy code into a non-lengthy code at the shortest code distance from the lengthy code to carry out the correction.
Thus, the error check in the prior art has a disadvantage of causing codes having an error to be screened out every check block, to thereby degrade transmission efficiency or a ratio of the number of codes which transferred correct data to the total number of codes transmitted. On the other hand, the error correction in the prior art also has a disadvantage of increasing the number of codes necessary for the error correction (codes unconcerned in the transfer of data), because of requiring to render the above-noted code distance substantially large, to thereby cause the transmission efficiency or a ratio of the number of codes concerned in the transfer of data to the total number of codes transmitted to be substantially reduced.
It should be noted that such disadvantages of the prior art are inevitably caused due to the fact that the prior art considers only an ex post facto remedy on the assumption of generaton of bit error and fails to reach an idea of reducing the probability of occurrence of a bit error itself.